From dc3e436b191a8f8d6f35fad952dd3dc314ccabf9 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 5 Nov 2018 11:04:02 +0900 Subject: [PATCH] Block creation of partitions with open references to its parent When a partition is created as part of a trigger processing, it is possible that the partition which just gets created changes the properties of the table the executor of the ongoing command relies on, causing a subsequent crash. This has been found possible when for example using a BEFORE INSERT which creates a new partition for a partitioned table being inserted to. Any attempt to do so is blocked when working on a partition, with regression tests added for both CREATE TABLE PARTITION OF and ALTER TABLE ATTACH PARTITION. Reported-by: Dmitry Shalashov Author: Amit Langote Reviewed-by: Michael Paquier, Tom Lane Discussion: https://postgr.es/m/15437-3fe01ee66bd1bae1@postgresql.org Backpatch-through: 10 --- src/backend/commands/tablecmds.c | 8 ++++++++ src/test/regress/expected/alter_table.out | 18 ++++++++++++++++++ src/test/regress/expected/create_table.out | 16 ++++++++++++++++ src/test/regress/sql/alter_table.sql | 16 ++++++++++++++++ src/test/regress/sql/create_table.sql | 14 ++++++++++++++ 5 files changed, 72 insertions(+) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index d271a50fc7f..6048334c755 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -1993,6 +1993,14 @@ MergeAttributes(List *schema, List *supers, char relpersistence, else relation = heap_openrv(parent, AccessExclusiveLock); + /* + * Check for active uses of the parent partitioned table in the + * current transaction, such as being used in some manner by an + * enclosing command. + */ + if (is_partition) + CheckTableNotInUse(relation, "CREATE TABLE .. PARTITION OF"); + /* * We do not allow partitioned tables and partitions to participate in * regular inheritance. diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out index 68cd3e5676d..0aa13b3cec2 100644 --- a/src/test/regress/expected/alter_table.out +++ b/src/test/regress/expected/alter_table.out @@ -3954,6 +3954,24 @@ ERROR: cannot attach a temporary relation as partition of permanent relation "p alter table temp_part_parent attach partition temp_part_child default; -- ok drop table perm_part_parent cascade; drop table temp_part_parent cascade; +-- check that attaching partitions to a table while it is being used is +-- prevented +create table tab_part_attach (a int) partition by list (a); +create or replace function func_part_attach() returns trigger + language plpgsql as $$ + begin + execute 'create table tab_part_attach_1 (a int)'; + execute 'alter table tab_part_attach attach partition tab_part_attach_1 for values in (1)'; + return null; + end $$; +create trigger trig_part_attach before insert on tab_part_attach + for each statement execute procedure func_part_attach(); +insert into tab_part_attach values (1); +ERROR: cannot ALTER TABLE "tab_part_attach" because it is being used by active queries in this session +CONTEXT: SQL statement "alter table tab_part_attach attach partition tab_part_attach_1 for values in (1)" +PL/pgSQL function func_part_attach() line 4 at EXECUTE +drop table tab_part_attach; +drop function func_part_attach(); -- test case where the partitioning operator is a SQL function whose -- evaluation results in the table's relcache being rebuilt partway through -- the execution of an ATTACH PARTITION command diff --git a/src/test/regress/expected/create_table.out b/src/test/regress/expected/create_table.out index 744b9990a6b..beb1acacc7f 100644 --- a/src/test/regress/expected/create_table.out +++ b/src/test/regress/expected/create_table.out @@ -910,3 +910,19 @@ ERROR: cannot create a temporary relation as partition of permanent relation "p create temp table temp_part partition of temp_parted default; -- ok drop table perm_parted cascade; drop table temp_parted cascade; +-- check that adding partitions to a table while it is being used is prevented +create table tab_part_create (a int) partition by list (a); +create or replace function func_part_create() returns trigger + language plpgsql as $$ + begin + execute 'create table tab_part_create_1 partition of tab_part_create for values in (1)'; + return null; + end $$; +create trigger trig_part_create before insert on tab_part_create + for each statement execute procedure func_part_create(); +insert into tab_part_create values (1); +ERROR: cannot CREATE TABLE .. PARTITION OF "tab_part_create" because it is being used by active queries in this session +CONTEXT: SQL statement "create table tab_part_create_1 partition of tab_part_create for values in (1)" +PL/pgSQL function func_part_create() line 3 at EXECUTE +drop table tab_part_create; +drop function func_part_create(); diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql index 68903466374..0352536fa5a 100644 --- a/src/test/regress/sql/alter_table.sql +++ b/src/test/regress/sql/alter_table.sql @@ -2607,6 +2607,22 @@ alter table temp_part_parent attach partition temp_part_child default; -- ok drop table perm_part_parent cascade; drop table temp_part_parent cascade; +-- check that attaching partitions to a table while it is being used is +-- prevented +create table tab_part_attach (a int) partition by list (a); +create or replace function func_part_attach() returns trigger + language plpgsql as $$ + begin + execute 'create table tab_part_attach_1 (a int)'; + execute 'alter table tab_part_attach attach partition tab_part_attach_1 for values in (1)'; + return null; + end $$; +create trigger trig_part_attach before insert on tab_part_attach + for each statement execute procedure func_part_attach(); +insert into tab_part_attach values (1); +drop table tab_part_attach; +drop function func_part_attach(); + -- test case where the partitioning operator is a SQL function whose -- evaluation results in the table's relcache being rebuilt partway through -- the execution of an ATTACH PARTITION command diff --git a/src/test/regress/sql/create_table.sql b/src/test/regress/sql/create_table.sql index 81fa7658b0d..da301c8b68b 100644 --- a/src/test/regress/sql/create_table.sql +++ b/src/test/regress/sql/create_table.sql @@ -730,3 +730,17 @@ create temp table temp_part partition of perm_parted default; -- error create temp table temp_part partition of temp_parted default; -- ok drop table perm_parted cascade; drop table temp_parted cascade; + +-- check that adding partitions to a table while it is being used is prevented +create table tab_part_create (a int) partition by list (a); +create or replace function func_part_create() returns trigger + language plpgsql as $$ + begin + execute 'create table tab_part_create_1 partition of tab_part_create for values in (1)'; + return null; + end $$; +create trigger trig_part_create before insert on tab_part_create + for each statement execute procedure func_part_create(); +insert into tab_part_create values (1); +drop table tab_part_create; +drop function func_part_create();